135 research outputs found

    Wind Resource Assessment in Building Environment: Benchmarking of Numerical Approaches and Validation with Wind Tunnel Data

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    ABSTRACT: In the framework of the wind energy network for distributed generation in urban environments for most South American countries, wind resource assessment studies have been carried out in activities to establish a suitable methodology to assess the wind potential in urban environments. Some methodologies are already published in research studies, and the wind tunnel is the most accurate solution to obtain insight into the wind resource when measurements are unavailable, which is the most frequent case. Nevertheless, besides its validity, one cannot disregard the high cost of producing a scaled urban model and access to a wind tunnel. In this sense, this paper compares results from a wind tunnel experiment and different numerical modeling approaches. Two commercial models (WindSim and Wasp Engineering) and one open-source CFD code (OpenFOAM) are used. The results from the modeling simulation concluded that CFD models could achieve lower deviations for the mean wind speed and turbulence intensity when compared with non-CFD models. With such results, CFD modeling is a promising tool for reliably evaluating wind potential in urban environments.info:eu-repo/semantics/publishedVersio

    Foreign Investment in Portugal and Knowledge Spillovers : From the Methuen Treaty to the Twenty First Century

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    This article looks at the impact of foreign direct investment (FDI) on host-country firms’ capabilities, industry competitiveness and long-term economic development. Focussing on the case of Portugal over a period of 300 years, it develops a framework of the types of knowledge spillovers, based on the behaviour of, and interactions between, foreign investors and local players. This study argues that the impact of FDI in Portugal has evolved in stages, from closed to interactive approaches, increasing the learning by local players. These ultimately lead to the long-term upgrade of firms’ capabilities, industry competitiveness and host-country economic development

    Impact of weather conditions on the windows of opportunity for operation of offshore wind farms in Portugal

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    The deployment of offshore wind parks face several challenges. Among them are the difficulties introduced by the atmospheric and sea conditions in accessing those wind parks. A window of opportunity is a timeframe when weather and sea conditions are acceptable and enable to perform specific tasks in the installation and operation/maintenance of the offshore wind park. This study identifies typical time periods of windows of opportunity to access three offshore Portuguese maritime regions. The accessibility conditions also take into account the system type transportation method for local access, namely, rubber boat, boat with OAS or helicopter

    Towards a high-resolution offshore wind Atlas : the Portuguese case

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    ABSTRACT: An accurate offshore wind resource assessment is a key tool for planning marine wind renewable exploitation. To achieve this goal, without resort to an extensive and costly network of anemometric stations or buoys, it becomes necessary to use the so-called atmospheric mesoscale models. This work presents a high spatial resolution (1x1 km) offshore wind resource Atlas for Portugal and the model calibration steps. During the calibration steps, the most adequate: i) atmospheric parameterizations - physics options, ii) initial and boundary conditions (IBC) meteorological datasets, and iii) data assimilation scheme were achieved through sensitivity tests using the common statistical metrics and hourly simulated/observational data. Results show that the most significant improvements are associated with the IBC dataset and the data assimilation scheme used. Thus, the results show that the assimilation procedures coupled with the new ERA-5 reanalysis dataset reduce significantly the errors of the wind speed and direction, especially the normalized mean square error. This reduction, depending on the different calibration setup, can be above 50%. The new Atlas confirms the previous indicators, Portugal presents a high wind power potential, especially for deep offshore regions.info:eu-repo/semantics/publishedVersio

    Learning difficulties with median and quartiles concepts in the 8th grade students: formula versus plot comparative study

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    na aplicação de algoritmos de cálculo da mediana e na sua interpretação, em alunos de diferentes níveis de ensino. Embora possam existir interações entre as causas que originam tais dificuldades, escasseiam estudos se e como as dificuldades (observáveis) no cálculo e na interpretação da mediana e dos quartis estão interligadas. Partindo de quatro situaçõesproblemas, são analisadas as respostas dadas por 81 alunos do 8.º ano de escolaridade de uma escola, identificando e classificando os erros cometidos no cálculo e interpretação da mediana e dos quartis. Usando o coeficiente de associação V de Cramer, investiga-se também, numa perspetiva quantitativa, a interdependência entre a capacidade de obter os valores da mediana, primeiro quartil e terceiro quartil e a de interpretar o efeito sobre a mediana de uma alteração de um dado, tendo por base um conjunto de dados e um diagrama de extremos e quartis. A análise estatística das respostas assinalou situações onde existem associações fracas ou moderadas; mais ainda, não revelou associação entre a dificuldade de obtenção analítica (via fórmula) e gráfica (via diagrama de extremos e quartis) da mediana, perante uma alteração de dados. Esta constatação leva a crer que os alunos veem a interpretação de resultados obtidos segundo aquelas duas abordagens (via fórmula versus via gráfica) como se de dois tópicos diferentes, não interligados, se tratasse.publishe

    How Individual Variations in the Perception of Basic Tastes and Astringency Relate with Dietary Intake and Preferences for Fruits and Vegetables

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    Background: Oral food perception plays a major role in food acceptance, although the way it relates with food preferences and final choices in adults is still debatable. The objective of the present study was to assess the relationship between gustatory function, dietary habits and fruit and vegetable preferences. Methods: Recognition thresholds, suprathreshold and hedonics were accessed for sweet, bitter, sour, salty and astringency in 291 adult participants. A Food Frequency Questionnaire (FFQ) and a questionnaire for assessment of preferences for individual fruit and vegetables were filled by the participants. Results: Three clusters were obtained: “most sensitive”, “less sensitive” and “less sensitive only for sour”. The less sensitive cluster showed lower preferences for fruit and vegetables and higher intake of sweets and fast foods, whereas higher preferences for sweet veggies were observed in the “most sensitive” cluster. Basic tastes and astringency hedonics did not associate with fruit and vegetable preferences, but the sensitivity for these oral sensations did. Conclusions: Taste and astringency sensitivities are related with the preference for fruit and vegetables, being also associated with some dietary habits. The effectiveness of the strategies to promote plant-based healthy food consumption may benefit from the knowledge of individuals’ gustatory function.info:eu-repo/semantics/publishedVersio

    Mapping flexibility of urban energy systems (FIRST) project: rationale and study design of an exploratory project

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    ABSTRACT: With the publication of the new Energy Performance of Buildings Directive, a large number of buildings are expected to become high energy performance and explore more the availability of renewable energy resources. Such buildings are often described in literature as nearly Zero-Energy Buildings (nZEB). Because renewable energy sources, such as wind and solar power, have an intrinsic variability, the zero-energy annual balance of nZEBs is difficult to reach at short time resolution (e.g. hourly). Thus, since electricity generation from small-scale solar renewable (typical case in Portugal) in individual households has limited capacity to be adjusted according to the power system needs, it is relevant to consider the demand flexibility potential, specially at community level (cluster of buildings). Unfortunately, there is a lack of studies on the impact of changes in electricity use at urban level on the future energy systems. Therefore, an approach addressing the energy flexibility (EF) in buildings may allow obtaining useful exploratory directions for the construction sector and related markets, policy makers and regulatory bodies. For these reasons, an exploratory project aimed at examining the potential of EF at the level of an existent neighbourhood in Lisbon was initiated. In this article we describe the objectives, design, and methods of the FIRST project, designed to map out the potential for EF in terms of benefits and costs in Lisbon.info:eu-repo/semantics/publishedVersio

    Solar Resource and Energy Demand for Autonomous Solar Cooking Photovoltaic Systems in Kenya and Rwanda

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    ABSTRACT: The challenges associated with traditional cooking methods in African countries, particularly the use of firewood and charcoal, which have negative impacts on the environment, health and human and economic development and safety, are addressed in this work. Given the high annual solar irradiation on the African continent, photovoltaic-powered electric cooking alternatives, such as electric pressure cookers (EPCs), are identified as a potential efficient, clean and affordable cooking solution. This work focuses on the potential of standalone solar electric cookers for use in rural African locations, namely, if this type of solution can satisfy cooking demand. Surveys and experimental data from several households in two different countries (Rwanda and Kenya) were collected. Specifically, the researchers performed a survey regarding cooking habits and an experimental campaign to determine real energy consumption profiles of EPCs. The main results are analyzed and discussed in this work. An assessment of the solar power capability to directly supply the EPCs’ energy demand, as determined from the experimental data, is performed. The findings indicate that, for the most commonly prepared food types, using EPCs saves considerable time in comparison with traditional cooking methods. In Rwanda, time savings range from 55% to 84%, while in Kenya, the time saved varies from 9% to 64%. Results show that, even for scenarios with high installed solar capacity, storage solutions are required to enable the PV-powered EPC system to supply more than 50% of meal demand.info:eu-repo/semantics/publishedVersio

    Improving Pharmacists Awareness of Inadequate Antibiotic Use for URTIs through an Educational Intervention: A Pilot Study

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    The inadequate use of antibiotics led to the development of multi-resistant bacteria that are now causing millions of deaths worldwide. Since most antibiotics are prescribed/dispensed to treat respiratory tract infections, it is important to raise awareness among health professionals to optimize antibiotic use, especially within the primary care context. Thus, this pilot study aimed to evaluate pharmacists' feedback about the eHealthResp platform, composed by an online course and a mobile application (app) to help in the management of upper respiratory tract infections (URTIs). Ten community pharmacists were invited to participate in this study, exploring the contents of the eHealthResp platforms and answering a content validation questionnaire composed by eight qualitative and thirty-five quantitative questions about the online course and mobile app. The eHealthResp platform is a comprehensive, consistent, and high-quality e-learning tool. Median scores of 5.00 were attributed to the course contents' and clinical cases' adequacy and correction. Most qualitative feedback was about completeness and objectivity of the course, and its usefulness for clinical practice. This study showed that eHealthResp has great potential as an e-health tool for the management of URTIs' symptoms, which may ultimately aid in reducing inappropriate antibiotic use

    Kinship Analysis and Pedigree Reconstruction of a Natural Regenerated Cork Oak (Quercus suber) Population

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    Cork oak (Quercus suber L.) is a valuable forest species in the western Mediterranean Basin due to its ecological value and the production of cork (a renewable natural material). Cork quality depends on the genetic background and cork oak environment, which has long been recognized. As no cork oak genetic trials with pedigree information were available, the inference of the genetic relatedness between individuals from molecular markers can potentially be applied to natural populations. This work aimed to investigate the potential of performing kinship prediction and pedigree reconstruction by SNP genotyping a natural cork oak population. A total of 494 trees located in Portugal were genotyped with 8K SNPs. The raw SNP set was filtered differently, producing four SNP sets that were further filtered by missing data, genotype frequency, and minor allele frequency. For each set, an identity by descent (IBD) matrix was generated to perform the relationship prediction, revealing from 22,114 to 23,859 relationships. Familial categories from the first to the third degree were able to be assigned. The feasibility of SNP genotyping for future studies on the kinship analysis and pedigree reconstruction of cork oak populations was demonstrated. The information produced may be used in further breeding and conservation programs for cork oakinfo:eu-repo/semantics/publishedVersio
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